freshwater resources (definitions)

freshwater

•relatively pure, with few dissolved salts

–Only 2.5% of Earth’s water is fresh, most is tied up in glaciers and ice caps (about 1% is actually available)

tributary

a smaller river slowing into a larger one

drainage basin/watershed

the area of land drained by a river and its tributaries (the entire system)

oxbow

an extreme bend in a river

oxbow lake

the bend is cut off and remains as an isolated, U-shaped body of water

floodplain

areas nearest to the river’s course that are flooded periodically (during flood season)

riparian

riverside areas that are productive and species-rich (the sides of the river)

wetlands

systems that combine elements of freshwater and dry land

freshwater marshes

shallow water allows plants to grow above the water’s surface

swamps

shallow water that occurs in forested areas

bogs

ponds covered in thick floating mats of vegetation

why are wetlands so important

they slow runoff

reduce flooding

recharge aquifers

filter pollutants

littoral zone

region ringing the edge of a water body

lots of plants and sunlight

benthic zone

extends along the entire bottom of the water body (bottom shit)

limnetic zone

open portions of the lake or pond where the sunlight penetrates the shallow waters

profundal zone

water that sunlight does not reach

less animals and oxygen

oligotrophic lakes and ponds

have low nutrient and high oxygen conditions (clear water)

eutrophic lakes and ponds

have high nutrient and low oxygen conditions (fuck ton of algae)

inland freshwater seas

large lakes that hold so much water, their biota is adapted to open water (mimics ocean)

groundwater

precipitation that does not evaporate, flow into waterways, or get taken up by organisms (just on the ground)

aquifers

porous sponge-like formations of rock, sand, or gravel that hold groundwater

zone of aeration

spaces are partially filled with water

zone of saturation

spaces are completely filled with water

water table

boundary between zones of aeration and saturation

aquifer recharge zone

any area where water infiltrates earth’s surface and reaches aquifers

confined/artesian in hydrologic cycle

water-bearing, porous rocks are trapped between layers of less permeable substrate, like clay

unconfined aquifer

no upper layer to confine it (recharged by surface water)

Dam

any obstruction placed in a river or stream to block the flow of water so that water can be stored in a reservoir

benefits and drawbacks of dams

benefits: power generation, crop irrigation, drinking water

drawbacks: habitat alteration, population displacement, sediment capture

water mining

withdrawing water faster than it can be replenished

desalinization

the removal of salt from seawater or other water of marginal quality

(good but requires a lot of energy)

distilling

hastens evaporation and condenses the vapor

reverse osmosis

forces water through membranes to filter out salts

xeriscaping

landscaping using plants adapted to a dry environment

point source water pollution

discrete locations of pollution (we know the source of the pollution)

ex. sewer pipes

nonpoint source water pollution

pollution from multiple cumulative inputs over a large area (pollution comes from multiple sources)

ex. farms, streets

pollution

the release of matter or energy into the environment that causes undesirable impacts on the health and well-being of humans or other organisms

most common types of pollution

nutrient pollution (eutrophication)

pathogens and waterborne diseases

toxic chemicals

sediment

thermal

nutrient pollution

from fertilizers, farms, sewage - leads to eutrophication

pathogens and water borne diseases

enters water supply through poorly treated human and animal waste

shit water

toxic chemical pollution

toxic chemicals enter water, poisoning animals and plants, altering aquatic ecosystems

suspended matter pollution

sediments/toxins enter water, changing aquatic habitats and killing fish

too much sediment limits light penetration

thermal pollution

changing temp of water body, warmer water holds less oxygen, suddenly cold water shocks ecosystem/animals

wastewater

water that has been used by people in some way (showers, sinks)

septic systems

the most popular method of wastewater disposal in rural areas (septic tanks contain waste and clean water)

primary treatment

the physical removal of contaminants in settling tanks (separating liquids from solids)

secondary treatment

water is stirred and aerated so aerobic bacteria degrade organic pollutants (good bacteria cleans water)

effluent

treated waste water is piped into rivers and oceans following primary and secondary treatment

grey water

waste water can be reclaimed

sludge

solid material remaining after water is removed (can make biosolids)

remediation

removing pollutants from water

pump and treatment of groundwater

pump out water, treat it and return

air sparging

injecting oxygen where contaminants adhere to the air bubbles

3 basic categories of groundwater remediation

physical

chemical

biological